1. Field of the Invention
This invention relates to surgical instruments and, more particularly, to a support for a laparoscopic surgical instrument to maintain a desired orientation of the instrument relative to a tissue through which the instrument extends.
2. Background Art
In performing laparoscopic surgery, an incision is made in a patient to admit a cannula which serves as a conduit for the introduction of selected surgical instruments into a body cavity. The body cavity in which the operation is performed is filled with a gas to distend the surrounding tissue to create a suitably sized operating space.
The inventor herein has designed structures to maintain the gas in the body cavity while allowing freedom of tilting movement for the surgical instrument. One such structure is shown in U.S. Pat. No. 5,002,557. This particular structure utilizes an elongate sleeve having an inflatable bladder at its distal end which is passed through the tissue into the body cavity. A collar with a conical sealing surface is slidable lengthwise of the sleeve. The distal end of the sleeve is passed through the tissue with the bladder deflated. Inflation of the bladder creates an annular shoulder which can be drawn up sealingly against the inside tissue surface. The collar is pressed into the tissue towards the bladder shoulder so that the bladder shoulder and collar captively embrace the tissue to thereby hold the sleeve in an operative position. The conical collar surface and bladder maintain a seal at the tissue incision even with the sleeve reoriented in use.
While the above structure affords a high integrity seal through a wide range of movement for the sleeve, it has one limitation. The basic instrument in U.S. Pat. No. 5,002,557 does not have any structure for maintaining a desired orientation of the sleeve. This feature is desirable to perform many conventional procedures. It is common to align the sleeve opening with a site at which more than one procedure is to be performed. The surgeon is usually required to remove and reinsert the same or different instruments. In the absence of some type of aligning structure for the sleeve, the surgeon is required to constantly manipulate the sleeve to access the same site. This is an inconvenience and time consuming. Further, certain procedures require the use of multiple instruments directed through separate incisions into a body cavity. The freely movable sleeves may reposition to cause interference between the various instruments therewithin. Furthermore, the conical structure limits the degree to which the sleeve can be tilted as the large end of the cone impinges on the opposing surface of the skin on the side to which the instrument is tilted.
The inventor herein has also developed certain guide structures in the form of adjustable jigs that can cooperate with an instrument. Exemplary structures are shown in my U.S. Pat. No. 5,201,742, entitled "Support Jig for a Surgical Instrument".
While the jig disclosed in U.S. Pat. No. 5,201,742 is was highly effective in terms of its versatility and stability, it has one drawback; that being that the tissue is required to flex significantly as the instrument is repositioned, due to the fact that the pivot point for the instrument is spaced a substantial distance away from the tissue.